Yes, I've loaded default settings after I upgraded bios to 0013 -- the board was shipped with 0012. I've suspected that the newer version might solve this. However, it did not.
As for why to disable fan control: I have manual fan speed controllers on each fan connected. I have set them to levels which guarrantee adequate cooling (having measured temperatures under full load), while being reasonably quiet. This is one of many PCs I have, so I have to keep the noise at minimum. Now, Intel boards in general are known to have quite satisfying fan control. On the other hand, if I am sure the fans are running fast enough to get the job done, I do not want to let the board mess with them. I just want the feedback if anything goes wrong -- overheating, fan stopped, etc.
And, more generally: disabling the fan control is a feature of the board, since the setting is present and accessible. I'd like to be able to exploit every feature, and this one just does not work.
Not that it matters in this cause, but yes. Twice.
First installation was on bios 0012 to test the system under full load. I measured temperatures and adjusted fan speeds. Then I upgraded to 0013, installed OS the 2nd time (on another hdd) and verified measurements from then 1st install.
OS is running stable for 2 days now. The issue I opened this thread about is imho not related to the OS, but to the board itself.
The only downside is that I had to connect the fans directly to +12 from PSU, not to the board. This way, they are running at speeds I want. However, I am not able to determine if any of them fail. (in the OS) I can only measure components' temperatures. It would be nice to be able to monitor fans directly through the board, to have an "early warning" if anything happens, as opposed to "late warning" from temperature sensors.
For the record, the OS in question is Win7 Ultimate/64b.